<!DOCTYPE html>
<html lang="zh-CN">
    <head>
        <meta charset="UTF-8" />
        <title>12_盒子模型-特点-浮动元素的顶边</title>

        <style>
            #wrapper {
                width: 300px;
                height: 400px;
                border: 5px dashed red;
            }

            #d1 {
                width: 100px;
                height: 100px;
                border: 1px solid black;
                background-color: green;
            }

            #d2 {
                float: left;
                width: 200px;
                height: 100px;
                border: 1px solid black;
                background-color: aqua;
            }

            #d3 {
                float: left;
                width: 50px;
                height: 200px;
                border: 1px solid black;
                background-color: tomato;
            }


        </style>
    </head>
    <body>
        <div id="wrapper">
            <div id="d1"></div>
            <div id="d2"></div>

            <div id="d3"></div>
        </div>
    </body>
</html>